Method of preparing perforated pita bread

ABSTRACT

After pita dough has been rolled and prior to baking of the dough to form pita bread, the flat pancake-like dough form is weakened along a perforation or score line on at least one side of the dough form. In the baking process the dough form seals and inflates to form the central void characteristic of pita bread. The perforation or score line forms a weakened section in the inflated skin of the baking dough so that the rupture of the pita skin during the baking process occurs preferentially at the perforation or score line.

BACKGROUND OF THE INVENTION

Pita bread is a common staple in middle eastern countries and in recentyears has enjoyed considerable and increasing popularity in other areasof the world. This popularity is due in part to the convenience of usingpita bread for making a sandwich since the bread, when torn, forms apocket which may be filled with meat, cheese, and other edible material.

In its most common form pita bread is in the shape of a large flatpancake, typically four to eight inches in diameter and one eighth tothree eighths inches in thickness. Because of the process used in bakingthe pita bread, this flat disk actually comprises two outer layers orskins which are easily separated by the user.

Typically, the user will make a sandwich by tearing the pita bread inhalf, forming two semi-disks which can each be used to make a sandwich.Alternatively, the pita bread may be torn, cut, or otherwise severed toform a large and small disk segment, with the large disk segment beingused to make a sandwich. Finally, not uncommonly, the pita bread may becut or torn along one circular edge so that the entire pita bread may befilled with edible material to make a larger sandwich.

The double layer form which is characteristic of pita bread results froma baking process which is likewise characteristic of pita bread. In thisprocess a ball of dough is rolled to form a large flat dough disk, notunlike a large pancake in appearance. The disk is baked in an extremelyhot oven, typically in excess of 500° fahrenheit on a flat supportsurface. This rapid baking process causes the bread dough to initiallysear and to thus seal the top, bottom, and edge surfaces of the doughdisk. The dough in the central portion of the pita then bakes and, as aconsequence of the baking process, liberates gas and steam from thedough. This gas and steam creates pressure within the dough disk whichinflates the disk. Since the gas is unable to escape through the sealedperifory of the disk, this inflating process separates the upper andlower surfaces of the disk form so that during the baking process thepita bread resembles an inflated football. This inflation continuesuntil the pita is filled to capacity with steam and gas and the pitathen ruptures at its weakest surface location so that additional steamand gas created by the continuing baking process can escape.

At the completion of the baking process the pita bread is allowed tocool. As the gasses within the pita bread cool and continue to escapethrough the rupture in the pita skin, the pita again assumes a flat,pancake-like appearance. However, since throughout most of the bakingprocess the two skins of the pita bread are separated by the expandedform of the dough during baking, the pita bread, in its final form, hasa distinct upper and lower layer.

A common use for pita bread is the formation of a sandwich. Typically, auser will tear the pita bread in half, forming two semi-disks of dough.These semi-disks will have a relatively straight edge on one side,exposing the two distinct layers of the pita bread, and will have asealed semi-circular remaining edge. The user can then separate thelayers along the torn or cut straight edge and spread these layers,forming a pocket with the pita bread half. Edible material such asmeats, cheeses, etc, may be stuffed into the open pocket to form asandwich. One reason for the popularity of this type of pita sandwich isthe fact that the pita bread half forms a natural pouch which isrelatively durable and thus not likely to spill when the sandwich iseaten, and which also has less bread than more common sandwiches, thusyielding a lower calorie sandwich.

Alternatively, sandwiches are typically formed with pita bread bycutting or tearing the pita bread at locations other than along itsdiameter. For example, it is not uncommon to form a sandwich by tearingalong a cord of the pita disk removed from the diameter to form a largepocket segment and a small pocket segment, the large pocket segment usedto make a single, larger sandwich from the pita bread. In addition, itis not uncommon to cut or tear the pita bread along a circular linefollowing a portion of the circumference of the pita bread to make asingle, large pocket from the entire pita bread, and thus a largesandwich.

Because the location of the baking-induced rupture in the pita bread isunpredictable, occurring at the weakest surface of the pita bread duringthe baking process, sandwiches formed in the above described mannersvirtually always include a rupture. Even when the pita bread is torn inhalf to make two sandwich pouches, one of these sandwich pouches willinclude a baking-induced rupture. The rupture may also occur across thetear or cutting line when the sandwich is made, leaving a torn edge atwhich the stresses induced during the sandwich making process willcommonly cause further tearing and an unsightly sandwich. The rupture inthe pita bread, of course, provides a location where sandwich fillingmaterial can easily leak or fall from the pita bread pocket and alsocauses a stress concentration point where further tearing of the naturalpouch is likely. These undesirable results are a natural consequence ofthe pita baking process and have reduced, to some extent, theattractiveness of pita bread as a sandwich encapsulater.

An additional disadvantage of typical pita bread is the fact that,unless the bread is cut with a knife, tearing of the pita breadtypically creates an uneven edge which follows the weak portions of thebread's surface. This increases the difficulty in making a neatappearing sandwich or pair of sandwiches from pita bread.

SUMMARY OF THE INVENTION

The present invention involves a process used during the baking of pitabread which increases the utility of pita bread for sandwich makingwithout interfering with the normal pita baking process. After the doughhas been rolled to form the pancake-like disk, and prior to baking, thedough is weakened along a line which will ultimately form the tear linefor making sandwiches. This weakened line may either be formed along thediameter of the pita bread or parallel to a diameter, but offset fromthe center of the pita bread, or along a circular edge of the doughform.

The weakened line in the dough form may be formed either by perforatingthe dough along the weakened line or by simply making the dough formthinner along an ultimate tear line. In either case, as the dough isbaked and the pita bread inflates, the weakened line in the dough formcreates a location where the skin of the pita bread will preferentiallyrupture. Thus the dough form is not severed sufficiently to prohibitnatural inflation of the pita dough form into a ball-like shape, butonly sufficiently to cause the steam and gas from the inside of thebaking form to preferentially escape along the ultimate tear line.

The weakened preferential rupture line is formed in the disk of dough bya serrated cutter which may be pressed into the dough or a serrateddisk, which rotates above a conveyor carrying the dough disk into thebaking oven. In either case it has been found that serrations permit thedough form to be scored or thinned without interfering with the normalbaking process. It is believed that, even if the dough is pierced ateach serration, the dough nevertheless re-seals prior to the bakingprocess and during the initial stages of the baking process so that theserrations simply yield a weakened line rather than holes in the surfaceof the dough form which would prohibit the inflation necessary fornormal baking of pita bread.

The weakened section of the pita surface creates a preferential ruptureline as well as a weakened line for ultimate tearing by the user. Thus,the user, in making a sandwich, will tear the pita bread along theweakened line, coincident with the rupture line, so that the sandwichpockets which are formed by the user will not include a baking-inducedrupture. This forms a much neater sandwich pouch than was previouslypossible, and avoids leakage of the sandwich filling. In addition, theweakened line along the bread's surface facilitates tearing by the userso that a relatively neat, straight-line tear may be made across thepita bread to form one or two sandwich pockets.

These and other advantages of the present invention are best understoodthrough the following detailed description of the product and theprocess for making it. This description makes reference to theaccompanying drawings, in which:

FIG. 1 is a schematic perspective view of a pita bread manufacturingsystem which includes serrating disks in accordance with the process ofthis invention.

FIG. 2 is an enlarged perspective view of that portion of the apparatusof FIG. 1 which accomplishes the perforating process of the presentinvention;

FIG. 3 is an enlarged perspective view of a pita dough form beingprovided with a preferential rupture line by one of the disks of FIGS. 1and 2;

FIG. 4 is a schematic flow chart illustration showing the form of thedough and pita bread during the various processes which occur in theapparatus of FIG. 1;

FIG. 5 is a cross-sectional view of the pita bread taken along lines5--5 in FIG. 3 to show the weakening of the dough along the preferentialrupture line;

FIG. 6 is a perspective view showing the use of the preferential ruptureline for providing a preferential tear line useful in the formation ofsandwich pockets from pita bread;

FIGS. 7a through 7d show alternate pita bread shapes and exemplarypreferential rupture and tear lines in accordance with the presentinvention;

FIG. 8 shows a cutting die which may be used for forming preferentialrupture lines along the circumference of circular pita bread; and

FIG. 9 shows a pita dough form after perforation by the die of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring initially to FIG. 1, apparatus for manufacturing and bakingpita bread is shown schematically. In a typical apparatus, a mixer 10blends the various ingredients used in making pita bread dough. Thus,dough is added to a dividing stage 11 through a hopper 13. This dough isrounded and formed into individual spheres or balls of dough in therounding stage 11, which are then transported on a conveyor 14 to anintermediate rising or poofing apparatus 15. Note should be made of thefact that initial proofing occurs between the mixer 10 and divider 11.In the rising or poofing apparatus 15 the dough balls are subjected towarm temperatures so that the dough will rise to form larger spheres orballs. These larger spheres or balls are then transported on multipleconveyor belts 17 and pass beneath an initial pair of rollers 18 and 19which form the balls or spheres into flat oval shapes resembling ovalpancakes.

Referring to FIG. 4, the initial form of the dough balls is shown as 11ain the form that the dough balls exit the dividing apparatus 11 ofFIG. 1. During the rising process which occurs in the poofing or risingchamber 15, the dough enlarges in volume and typically maintains theshape as shown at 11a in FIG. 4. The initial rolling operation providedby the roller 18 flattens the dough balls to the shape 18a of FIG. 4,and the rolling operation of the roller 19 yields the oval pancake-likeshape 19a shown in FIG. 4.

Referring again to FIG. 1 the dough is next passed from the conveyors 17to a conveyor 21 which transports the dough in a direction which isperpendicular to the direction of transportation on the conveyors 17. Onthe conveyer 21 the dough passes under an additional roller 23 whichpasses over the dough in a direction which is normal to the passage ofthe rollers 18 and 19, yielding the circular flat shape shown at 23a inFIG. 4. The pita bread in the form shown at 23a is ready for baking and,if baked in this form, would yield typical pita bread. Referring againto FIG. 1, the dough form passes through the apparatus used in thepresent invention which is shown generally at 25, into a final proofer27, transferred by the conveyor 21. Referring to FIG. 4, the appratus ofthe present invention forms a preferential rupture line 26 in the doughform 25a prior to baking.

The pita bread is transferred from the final proofer 27 to an oven 31 ona conveyor 29. When the pita bread is baked in the oven 31 (FIG. 1), itexpands into a hollow ball or sphere as shown at 31a in FIG. 4. Aspreviously described and is well-known in the pita bread baking art, thetemperature of the oven 31 is high enough so that the dough form willinitially sear and seal on its outside surface, preventing the escape ofgas from the pita bread dough. As the dough continues to bake, steam andother gas is formed by the baking process. This steam and other gas iscaptured within the dough form and causes the dough form to inflate intothe shape shown at 31a in FIG. 4, separating the upper and lowersurfaces of the pita bread into two distinct layers. This steam andother gas will ultimately completely fill the void within the ball orsphere 31a and, as the baking continues, must rupture the skin of theball or sphere at its weakest point. Because a preferential rupture line26 has been formed along the surface of the pita bread, this rupturewill preferentially occur at some location along the preferentialrupture line 26, as shown at 28 in FIG. 4.

Referring again to FIG. 1, the pita bread, now baked completely, passesfrom the oven 31 on a conveyor 33 into a cooling chamber 34 in which thepita bread is gradually cooled. During this cooling, the remaining gaswithin the pita bread will escape through the rupture 28 so that thebread again flattens into the characteristic pita bread shape shown at34a in FIG. 4. After cooling, the pita bread is carried on a conveyor 36to a packaging apparatus 38 in which the pita bread is stacked andpackaged for sale.

Referring now to FIGS. 2 and 3, the details of the apparatus used tocreate the preferential rupture lines on the pita bread dough atlocation 25 of FIG. 1 will be explained in more detail. The conveyor 21is in the form of an endless belt. The pita bread, prior to arrival atstation 25 has been accurately positioned so that, for example, thedisk-shaped dough forms pass through the proofer six abreast as shown inFIG. 2. A driven shaft 37 carries a corresponding set of six perforatingdisks 39 which are best shown in FIG. 3. These disks 39 advantageouslyinclude a serrated edge 41 and the disks 39 are positioned, as shown inFIG. 2, along the length of the driven shaft 37 to coincide with thecentral diameter of the respective dough forms 25a.

The height of the driven shaft 37 is adjusted by a pair of threadedadjusting rods 42 which support the driven shaft 37 in pillow blocks 43.The driven shaft 37 is thus free to rotate in the blocks 43 and itsvertical position is adjustable by rotating a pair of adjusting nuts 45which are threaded onto the rods 42 and bear against the top of a pairof supporting brackets 49.

FIG. 5 shows a cross-sectional view of the pita bread along lines 5--5of FIG. 3 after serration by the serrating disk 39. It will be seen thatthe disk 39 advantageously does not pierce the pita dough formcompletely at any point, but rather thins the dough at the points marked51 and partially ruptures the dough below this thinning point as shownat 53. This thinning and rupturing process occurs along a line ofpreferential rupture 26 shown in FIG. 3. This preferential rupture line26 in the embodiment shown in FIGS. 2, 3, and 5, occurs diametricallyacross the center of each pita dough form and creates a weakened linealong the surface of the pita dough.

Referring again to FIG. 2, in the preferred embodiment, the driven shaft37 is connected, as by a chain enclosed within a housing 55, to a motor57, and is driven in synchronism with the belt 21 so that the tangentialvelocity at the edge of the disks 39 is identical to the linear speed ofthe belt 21. This causes the edge 41 of the disks 39 to roll along thetop of the pita dough form 25a without slipping.

Alternatively, the friction between the dough form 25a and the disks 39may be used to rotate the disks 39, thereby eliminating the motor 57,although the embodiment shown in FIG. 2 is preferred.

The height of the driven shaft 37, and therefore the height of the disks39, is accurately adjusted by rotation of the nuts 45 so that each ofthe six-abreast pita dough forms 25a is identically weakened by thedisks 39. Specifically, the height of the disks 39 should be such thatthe serrated edge 41 reduces the thickness of the pita dough form byapproximately 50% at the maximum point of indentation. It has been foundthat the process will function even if the serrated edge 41 completelypierces the pita dough form at the deepest point of penetration. Withthis deep penetration, the dough, on passing through the final proofer27 (FIG. 1), will partially seal the penetration, resulting in aweakened line which will cause preferential rupture of the pita breadalong this preferential rupture line 26.

As previously explained in reference to FIG. 4, the pita dough 31a, uponinflation during baking, will preferentially rupture along this weakenedline 26. Referring now to FIG. 6, it can be seen that the user, inpreparation for making a pita sandwich, can easily tear the pita breadin half, since the same preferential rupture line 26 which causes thepita dough form to rupture, weakens the skin of the pita bread,facilitating a neat tear line 26 within ragged edges. Even moreimportant is the fact that this neat tear line is coincident with thepreferential rupture line 26 so that the rupture in the pita bread whichoccurs during baking will exist along the tear line 26 of FIG. 6. Thus,each half 31b and 31c of the pita bread will be rupture free. Thus, whena sandwich is made from these halves 31b and 31c, there will be nobaking-induced rupture to cause the sandwich ingredients to fall fromthe natural pocket.

As shown in FIG. 7a, it is possible to eliminate the second roller stage23 of FIG. 1, resulting in an oval pita form 59 with a preferentialrupture and tear line 61, as opposed to the circular disk shape morecharacteristic of pita bread. Likewise, as shown in FIGS. 7b and 7c, themixing and rolling operation of FIG. 1 may be altered to form square orrectangular pita bread forms 61 and 63 which may be weakened alongeither a diagonal preferential rupture line 65 as shown in FIG. 7b, or adiameteric preferential rupture line 67 as shown in FIG. 7c.

Likewise, such a square pita bread form 69 is shown in FIG. 7d. In thisfigure, however, the preferential rupture line 71 has been formedadjacent one edge 73 of the square pita dough 79. In this case, the usermay tear the pita bread along the preferential rupture and tear line 71,discarding the edge 73 and yielding a large pocket for the making of asandwich from virtually the entire pita bread form 69.

In a manner similar to that shown in FIG. 7d, it is sometimesadvantageous, especially for making larger sandwiches, to be able totear a circular pita bread 75, as shown in FIG. 9, along a portion ofits circular edge 77. This may be accomplished in accordance with thepresent invention by utilizing a cutter 79, shown in FIG. 8, whichincludes plural semi-circular serrated knives 81 mounted on a bar 83which is, in turn, reciprocated by a pair of driving shafts 85. Thedriving shafts 85 may be reciprocated, for example, hydraulically orpneumatically, beneath the supports 49 shown in FIG. 2. This operationmust, of course, be carefully timed so that the bar 83 is hydraulicallyor pneumatically lowered as the pita dough forms arrive at the properlocation beneath the bar 83, yielding a preferential tear line 87 alongthe edge 77 as shown in FIG. 9. The user may then tear the edge of thepita bread along the preferential rupture and tear line 87, discardingthe edge 77 in order to make a large sandwich from virtually the entirepita bread 75, stuffing the ingredients into the open edge.

As will be seen, each of the embodiments shown in this applicationincludes a weakened line formed in the dough prior to baking. Thisweakened line causes a preferential rupturing of the pita bread at theweakened line during baking so that this preferential rupture line willbe coincident with a tear line which the user may utilize to open thepita bread to form pockets for the formation of sandwiches. Theweakening of the dough is sufficient to cause preferential rupturing,but is not sufficient to interfere with the normal inflation of theentire pita bread as a unit as shown at 31a in FIG. 4, since suchinterference would prohibit proper baking of the pita bread dough.

What is claimed is:
 1. A method of manufacturing pita bread,comprising:forming pita dough into a flat dough form; weakening saidflat dough form along a line sufficiently to provide a preferentialrupture line; baking said flat dough form such that baking-induced gasesinflate said dough form to create the characteristic pocket in the breadand subsequently cause said dough form to rupture in response to thebaking-induced inflation pressure along said preferential rupture line;and cooling said dough form to yield a flat, two-layer pita breadruptured along said preferential rupture line.
 2. A method ofmanufacturing pita bread as defined in claim 1 wherein said forming stepforms a circular, flat dough form and wherein said weakening stepprovides said preferential rupture line along the diameter of saidcircular dough form.
 3. A method of manufacturing pita bread as definedin claim 1 wherein said forming step forms a circular, flat dough formand wherein said weakening step provides said preferential line offsetfrom the diameter of said circular dough form.
 4. A method ofmanufacturing pita bread as defined in claim 1 additionally comprisingtearing said pita bread along said preferential rupture line to form apocket for making a sandwich.
 5. A method of manufacturing pita bread asdefined in claim 1 wherein said weakening step comprises serrating saiddough form along said line.
 6. A method of manufacturing pita bread asdefined in claim 1 wherein said weakening step comprises passing saiddough form beneath a rotating disk to reduce the thickness of said doughform along said preferential rupture line.
 7. A method of manufacturingpita bread as defined in claim 6 wherein said weakening step comprisesforming a non-uniform preferential rupture line in said dough form byusing a serrated edge on said disk.
 8. A method of manufacturing pitabread as defined in claim 1, wherein said weakening step comprisesimpressing a blade into said dough form.